Process of making negatives



PROCESS OF MAKING NEGATIVES Fi led Dec, 12, 1928 INVENTOR.

' WILLIHM HEINEEKE,

BY Q Q ATTORNEY.

' Patented June 13, 1933 WILLIAI EEINEGKE, 01 MEDIA, IOWA rnocnss or mine nnea'rivns Application med December 12, 1328. Serial no. 325,664.

My invention consists in a chemical process of producing a negative for use in photoprinting.

In my Patent No. 1,700,262, dated January 5 29, 1929, I have described a method of making negatives for printing process or photographic purposes, comprising pulling an inked impression on the sensitized side of a sheet or film, plate, or the like, developing the film, or the like, removing the impression and fixing.

The present invention differs from the former in that the impression is pulled on a non-photographic, but chemically sensitive film,'sheet, plate of the like, which by being 'brought in contact with a suitable reagent, preferably in a gaseous state, is altered in its properties as regards the passage of the actinic rays in those portions where such reaction has taken place.

to the former method as disclosed in my said patent, the action of light does not enter in any manner whatsoever into the results ob-- tained by my new process. The new sensitive material may consist either in a supporting film base and a sensitized substance thereon, or in a film, or sheet, in which the sensitized substance has been embodied in the process of manufacture, or has been absorbed by impregnation, or the like. The basis for this new process of producing a negative is the well-known reaction of a number of organic as well as inorganic substances with suitable reagents resulting in the formation of new compounds indicated by changing to non-actinic color.

The object f the present invention is to provide means for transferring designs on lithographic or typographic printing surfaces to sensitized offset press plates, and the like, without the aid of camera, contact printing frame, dark room and other photogrpahic equi ment, resulting in a cons derable savin in time and labor. 7

referably, I emplms base a transparent or translucent paper, or the like, with or without a substratum, and an impregnated la er thereon. Said layer may consistof a su ce, or substances, serving as a vehicle so for and containing a chemical, or chemical In contra-distinction compound, of organic or inorganic nature, capable of reacting with another chemical, or chemical compound, to reverse the actinic character of the said substance, entirely independent of the action of light.

An impression is pulled on a proofing or power press, for instance, or in some other manner, on the impregnated side of the sheet or film, which is then brought in contact with certain other chemical substances, which, in reacting with the chemical substance, or sub= stances, embodied in the layer of the film, undergo a change in color, thus producing a negative. It is also possible to embody the reagent with the compound used for printing the design and pulling the impression on the layer made opaque either previously or after the pulling of an impression, for the purpose of rendering the portions covered by the impression transparent or translucent thus permitting the passage of actinic light.

Without in any way-limiting my invention to any particular procedure, or any particular substances mentioned herein as suitable for the above said purpose, I will now describe a process which will serve to illustrate a practical mode of operation having reference to the appended drawing. On this drawing, I have shown in Figs. 1-3 on a greatly exaggerated scale, transverse sections of portions of negatives produced in accordance with this invention.

I start with a sheet of paper, or film forming a base and indicated in Figs. 2 and 3 at B, which sheet or film, for the-purpose of this invention, is coated with a layer comprising a colloid impregnated, for instance, with a de-oxidizing agent, e. g. pyrogallol, said layer being indicated in Fig. 2 at A. After the pulling of an impression on the impregnated side of the film, the same is exposed to the action of an oxidizing agent in solution or gaseous state. The impression, marked I in Fig. 2 which serves as a protective cover to prevent reaction in the portions of the design is then removed by means of a suitable solvent, e. g. benzine, resulting in an actinic image on a non-actinic background. I

Instead of a colloid, I may also use as a vehicle for the reagent, or reagent embodied in the layer, any-other substance or substances capable of entering into solution or compound with suitable reagents and forming a layer or pellicle insoluble in water, such 5 other substances being, for instance, solutions of gums or resins in ethyl acetate, alcohol, or other suitable solvents.

Also, instead of deoxidizing agents, like pyrogallol, digallic acid, and the like, I may use for the impregnation of the layer compounds capable of reduction, as, for instance, metallic salts, or organic compounds or substances, e. g. aniline or phenol derivatives, which in reaction with suitable reagents in solution, solid or in the gaseous state will be capable, directly or in secondary reaction, of changing in color impervious to actinic light, as indicated by A" in Fig. 3. The inked impression marked I serves to either prevent any chemical reaction between the substances with which the layer has been impregnated and the reagent producing the chemical reaction, or to produce a second and independent reaction with the impregnated layer for the purpose of clearing the portions covered by the impression for the passage of actinic light, as, for instance, efiected by the application of a solution of potassium cyanide in glycerin to a colloid layer impreggo 'nated with silver nitrate, forming organic silver compounds.

According to Fig. 1, the chemically active member is directly embodied in the base or film A, the impression being marked lln all the figures, the portions exposed to the action of the reagent are shown at a, while the portions protected by the impression I against such action are shown at a.

The new method, as will be seen, difi'ers from photographic methods and products in that the reduction of the chemical substances, embodied in the sensitized layer receiving the impression, is not brought about by the action of light, or of light plus reducing agent, but the desired results are brought about by mere chemical reaction, independent of the action of light. Allowing that among the possible substances some selected for use as reagents may happen to belong to the light-sensitive class, such light-sensitiveness would appear as makin these substances less desirable and suite le for the purpose of this method than otherwise, because for practical reasons of operation the impregnated film must necessarily be handled in daylight, or any light conditions existing in printing plants. The darkening process, called development in photography, rests on the action of light on certain light-sensitive compounds and the selective darkening of certain portions of the image, previously having been exposed to light with the efi'ect of the formation of a latent image, by means of reducing agents. In the present method, as distinguished from aeaaeea the photographic method, there is taking place, as the essential and operative principle, a chemical reaction which is entirely independent of light-action on the reagent, or reagents, both, those forming the reduction or oxidation product and the reducing or oxidizing agent, or agents.

The present invention, therefore, provides a method for the production of negatives by chemical means alone, direct from any printing surface, like metal or stone, and the like, that will result in a considerable saving in time and labor over the practice now in general use.

Furthermore, the present invention, in combination with a waterproof or moistureproof material serving as base and a waterproof or moistureproof layer thereby provides means for the production of negatives in the manner described heretofore, suitable for multi-color work requiring close register, as the chemical reaction necessary for the production of a negative may be effected Without the use of aqueous solutions and on moisture-resisting material.

The term negative used herein is in no way to be understood in the photographic sense, because the present invention has no relation to photographic processes. The said term is meant in a generic way and has been chosen with regard to its final purpose of producing a printing image on the press plate in which generally the lights and shades are the opposite of those of the film object.

I claim:

1. The method of producing a negative for use-in photo-printing which comprises applying to a film element a substance servingas a'vehicle for and containing a chemical adapted to react with another chemical to reverse the actinic character of the substance entirely independent of the action of light, masking portions of the applied substance, subjecting the exposed portions of the substance to a chemical reactive with the chemical of the substance to reverse the actinic character of the substance, and removin the masking means.

2. The method of producing a negative for use in photo-printing which comprises applying to a film element a substance serving as a vehicle for and containing a chemical adapted to react with another chemical to render the substance impervious to the passage of actinic rays entirely independent of the action of light, masking portions of the applied substance, subjecting the exposed portions of the substance to a chemical reactive with the chemical of the substance to render the exposed portions of the latter impervious to the passage of actinic rays, and removing the masking means.

3. The method of producing a negative for use in photo-printing which comprises applying to a film element a substance serving as a vehicle for and containing a chemical adapted to react with another chemical to render the substance pervious to the passage of actinic rays entirely independent of the action of light, masking portions of the applied substance, subjecting the exposed portions of the substance to a chemical reactive with the chemical of the substance to render the exposed portions of the latter pervious to the passage of actinic rays, an removing the masking means.

4. The method of producing a negative for use in photo-printing which comprises applying to a film element a substance serving as a vehicle for and containing a chemical adapted to react with another chemical toefi'ect a change in color of the substance entirely independent of the action of light, masking portions of the applied substance, subjecting the exposed portions of the subtance to.a chemical reactive with the chemical of the substance to effect a change in color of the exposed portions of the substance, and removing the 'masking means.

In testimony whereof I afiix my signature.

WILLIAM HEINECKE. 

